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Correction status：Uncorrected
Teacher's comments：
Collection
Collection
总结：没有听明白ajax如何回传数据，网上百度没有找到，一直郁闷中。
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>文件上传工具</title>
<style type="text/css">
div{
width:360px;
margin:auto;
border:4px solid blue;
border-radius:20px;
}
form{
width:360px;
margin:10px auto;
text-align:center;
}
h2{
text-align:center;
}
button{
width:80px;
height:30px;
background-color:green;
color:white;
border:none;
cursor:pointer;
}
button:hover{
background-color:red;
}
</style>
</head>
<body>
<div>
<p><h2>文件上传工具</h2></p>
<form action="<?php echo htmlspecialchars($_SERVER['PHP_SELF']); ?>" method="POST" enctype="multipart/form-data">
<p><label for="file">文件名:</label><input type="file" name="file" id="file"></p>
<p><button type="submit" name="submit">提交</button></p>
</form>
<?php
// if (isset($_POST['submit']))
if($_SERVER['REQUEST_METHOD']=="POST")
{
if (!empty($_FILES['file']['tmp_name'])) {
$allowedExts = array("gif", "jpeg", "jpg", "png");
$tmp = explode('.', $_FILES['file']['name']);
$ext = end($tmp);
if (in_array($ext, $allowedExts)) {
if ($_FILES['file']['error'] > 0) {
echo '<p>错误原因是:<strong>';
switch ($_FILES['file']['error']) {
case 1:
echo '文件超过了php.ini配置中设置的大小';
break;
case 2:
echo '文件超过了表单中常量设置的大小';
break;
case 3:
echo '仅有部分文件被上传';
break;
case 4:
echo '没有文件被上传';
break;
case 6:
echo '没有可用的临时文件夹';
break;
case 7:
echo '磁盘已满,写入失败';
break;
case 8:
echo '上传意外中止';
break;
default:
echo '系统未知错误';
break;
}
echo '</strong></p>';
} else {
$dir = 'upload';
if (is_dir($dir)) {
// echo "当前目录下，目录".$dir."存在";
date_default_timezone_set("PRC");
$newName=date('Y').date('m').date('d').date('H').date('i').'.'.$ext;
if (move_uploaded_file($_FILES["file"]["tmp_name"], "upload/". $newName)) {
echo "<script>alert('上传成功！')</script>";
if (file_exists($_FILES['file']['tmp_name']) && is_file($_FILES['file']['tmp_name'])) {
unlink($_FILES['upload']['tmp_name']);
}
}
} else {
//无目录，立即创建
echo "<script>alert('当前目录不存在，已经建立完成！')</script>";
mkdir("upload");
}
}
} else {
echo '文件格式不对！';
}
} else {
echo "<script>alert('请上传文件！')</script>";
}
}
?>
<script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script type="text/javascript">
</script>
</div>
</body>
</html>点击 "运行实例" 按钮查看在线实例
